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UC Davis Comprehensive Cancer Center

UC Davis Comprehensive Cancer Center

What are clinical trials?

Most children with cancer are treated as part of a clinical trial. A clinical trial is a research study done to improve treatment. The goal of clinical trials is to see if a treatment is safe and how well it works in treating cancer.
In a clinical trial, children are followed closely over time to see which treatments offer the best chance for cure with the fewest side effects. New trials are planned based on results of past trials, as well as on what we know about the disease and about cancer treatments.

The findings from clinical trials add to knowledge and progress in the treatment of cancer. Since childhood cancer is rare, by trying different treatments and looking at the results, we can find out which treatments are the best much more quickly. In the 1960s, most children with cancer died. Since that time, cure rates have increased dramatically. Today, overall, more than 75 percent of children with cancer are cured. Organized clinical trials have helped to make the difference.

Following are answers to some commonly asked questions about clinical trials:

What are the benefits and risks of clinical trials?

You may  ask yourself, “How does my child benefit from being on a clinical trial”?

When treated on a clinical trial, your child receives the most up-to-date treatment. Just as your child will benefit from what was learned by clinical trials in the past, other children in the future will be helped by what we learn from clinical trials today.

Some risks from clinical trials are that the treatment may have side effects, your child may spend more time at the clinic or hospital to get the treatment or tests done, and the treatment may not work for your child's disease.

Does my child have to be in a clinical trial?

To help you make a decision, you may want to get a second opinion. A doctor who is not a part of your current health-care team will look at your child's history, laboratory findings and exam. The doctor will give you his or her opinion about your child's treatment plan. Some insurance companies require a second opinion before starting treatment. Your doctor may refer you to another expert doctor. You also may call the National Cancer Institute's toll-free number, 1 (800) 4-CANCER, or visit its Web site to find cancer centers and doctors all over the country.

You may choose not to enter your child in a clinical trial. You may also choose to remove your child from a trial at any time. Your choice will not affect how the health-care team feels about your or your child. Your child will still receive the best possible care.

If you decide not to enroll in a clinical trial, your child will receive what is known as standard treatment. Standard treatment is the best known therapy at the time.

What is the Children's Oncology Group?

The Children's Oncology Group is the largest pediatric clinical trials group. Over 240 hospitals participate in COG. For each new trial, a group of doctors, nurses and other experts plans how the treatment will be given. Members of COG meet several times a year to learn from old trials, study the current trials and plan new trials.

How are trials reviewed?

After a review by experts in the Children's Oncology Group, a trial is sent to the National Cancer Institute for approval. Once approved by NCI, the trial is sent to your hospital's institutional review board. An IRB is a committee at a hospital or clinic that reviews a clinical trial to make sure that the rights of patients are protected. Each trial is reviewed many times by many experts before any treatment center can start a trial.

What is randomization?

Your child may be in a clinical trial that compares two or more treatment arms. Each arm offers a treatment that has been shown effective in other studies, but it isn't known yet if one treatment is better in some way. Usually one arm offers the standard treatment --  the current, best-known treatment. The other arm or arms may have slight changes or additions that may improve cure rates, control disease longer, cause fewer or less serious side effects, or result in fewer days spent in the hospital. To learn if one treatment is better, each child is assigned randomly to one of the treatment arms by a computer. Randomization is a process, like flipping a coin, that assures each child has a fair and equal chance of being assigned to any of the treatment arms.

In most studies, we do not know which treatment is better until all the children on the study have completed treatment and have been followed for several years. However, if one of the treatment arms is found to be better than the others while the trials in progress, the trial is stopped and all children are given the treatment with the best results. If for any reason the treatment is found not to be the best for your child, the plan will be changed. If a clinical trial is not currently open when your child is diagnosed, your child will receive the best standard treatment.

What is a "therapy delivery map"?

Your doctor or nurse will review the treatment plan or protocol for your child. Included in the protocol is a therapy delivery map, or TDM, which lists required treatments, tests and procedures. Along with the TDM, you will receive a medication and appointment calendar.

Keep in mind that each child is different and your child's TDM may change. These changes will depend on how your child responds to treatment. A delay in treatment is common if your child gets a fever or has low blood counts.

What should I know about informed consent?

After your doctor reviews the treatment plan with you, you will be asked to give your permission for your child to start treatment. This is called giving parental permission or informed consent . You will be asked to sign a form that describes the plan. This form lists the risks and benefits of the treatment and what other treatments may be available. When you sign the form, you are saying that you understand what the doctor has explained to you and you agree to start the treatment.

If your child is old enough to understand, he or she will be asked to agree with the treatment plan as well. When a minor (a child younger than 18 years old) agrees with the plan, the child is giving assent. Members of your health-care team will help explain the treatment plan to your child in words that he or she can understand.

Informed consent is a process that does not stop after you sign the form or start treatment. Every day in the hospital, or at each clinic visit, your doctor or nurse will talk with you about the plan of care. This is your chance to ask questions and decide whether or not you agree with the plan.

What questions should I ask?

Before meeting with your doctor, write down any questions you have. You may feel so overwhelmed that you can't think of any questions. Here are some examples of questions you may want to ask:

  • Does my child have to be on a clinical trial?
  • What type of cancer does my child have?
  • What is the stage of disease?
  • What does this stage mean?
  • What are the treatment choices?
  • Which treatment do you recommend and why?
  • How long will the treatment last?
  • What are the chances that this treatment will be successful?
  • How will we know if it is successful?
  • What are the risks of this treatment (short-term and long-term)?
  • What will my child have to do as a part of this clinical that is different from standard treatment?
  • How much will this treatment cost?
  • How can I help prepare my child for this treatment?

Bring a pen and paper to your meeting so you can take notes. You may want to ask a friend or relative to come with you to take notes for you.

What are the different types of clinical trials?

The different types of clinical trials are called phases. There are three phases. Each phase answers a different question about the disease or treatment. Clinical trials can be designed to study how to prevent cancer, how to treat it, or how to improve a child’s comfort or quality of life


Phase I



Test a new treatment in humans that has been tested in the laboratory.
Find the best way to give a new treatment.
Find the safest dose of a new treatment or the highest dose with the least side effects.
Learn how the body responds to a new treatment.


Patients are given a low dose of the treatment to see if side effects occur.
The doses are increased in groups of patients until harmful side effects are seen.


Trial offered only to patients whose disease has not responded to other less experimental treatments.

Potential benefits

Individual patients usually do not benefit from this type of study.
A very small number of patients may respond to the new treatment.
Future children benefit from what is learned in this type of trial.

Potential risks Side effects of new treatment may not be known.
Patients may feel discomfort or pain from the new treatment.
Patients may spend more time in the hospital or clinic to receive the new treatment or have tests done to evaluate the response.


Phase II



Learn if a new treatment works in patients with specific types of cancer.
Learn how a new treatment affects the body.


Patients with different types of cancer receive a new treatment using a dose that was found to be safe in a Phase I trial.
Patients are followed for side effects and response rates.


Trial offered only to patients whose disease has not responded to other less experimental treatments.

Potential benefits

A small number of patients may have a response from the new treatment.

Potential risks Benefits of the treatment are not known.
Patients may feel pain or discomfort from side effects.
Patients may spend more time in the hospital or clinic to receive the new treatment or have tests done to evaluate the response.


Phase III



Learn if a new treatment that is known to be effective in treating a specific type of cancer is better in some way (better cure rates, longer control of disease, fewer or less serious side effects, or fewer days in the hospital) than standard treatment for the disease.


Patients are assigned by a method called randomization to one of two or more treatment plans.


Patients with the same type of cancer are eligible for standard treatment.

Potential benefits

Trial offers the most up-to-date treatment with the best known response and cure rates.

Potential risks The new treatment being compared is thought to be at least as good as the standard treatment, but it is not known if the new treatment will be better than the standard treatment (that’s the purpose of the Phase III study).

How do I find a clinical trial for my child?

To find a clinical trial that might be right for your child, visit one of these sites:

For more information about trials at UC Davis Cancer Center, call (916) 734-2780.

Information is adapted from the Family Handbook for Children with Cancer. CureSearch/Children’s Oncology Group. Last updated 5/2007.